Have you ever met a person who left you wondering, "How could someone be so twisted? So evil?" Larry Mantle talks with author Barbara Oakley, whose studies suggest that people may be genetically predisposed to be bad. Drawing on recent advances in brain imaging, Oakley links the behavior of Hitler, Stalin, Mao TseDong, and even her own sister, and makes the argument that evil behavior may be caused by a brain disorder. If this is true, Larry Mantle asks, how responsible are malevolent people for their own behavior?